I've written a little xboxdrv script to play Grim Fandango through ResidualVM on Linux using an Xbox 360 controller.
Maybe it's not a full solution to the controller support problem, but for someone it might be a more comfortable temporary solution than using the keyboard.

I've set the script up to use both the left analog stick and the d-pad for movement with camera-relative mode in mind, but I personally preferred to play with character-relative mode and using the D-Pad alone for maximum precision.